• Journal of the Korean Society of Radiology
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• v.16 no.7
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• pp.975-984
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• 2022

Since a linear transducer has an area of interest equal to the length of the transducer, the area of interest can be expanded using the virtual convex function installed in the device.However, it was thought that the change in the direction of the ultrasonic sound velocity according to the change in the visual area of interest would affect the image quality, so this was objectively confirmed. For this study, image evaluation and SNR·CNR of the phantom for ultrasound quality control were measured. As a result, in the phantom image evaluation, both images were able to identify structures in functional resolution, grayscale, and dynamic range. However, it was confirmed that the standard image was excellent in the reproducibility of the size and shape of the structure. As a result of SNR·CNR evaluation, SNR·CNR of most trapezoidal images was low, except for structures at specific locations. In addition, through the statistical analysis graph, it was further confirmed that the SNR and CNR for each depth decreased as the size of the cystic structure decreased. Through this study, it was confirmed that the use of the function has the advantage of providing a wide visual area of interest, but it has an effect on the image quality. Therefore, when using the virtual convex function, it is judged that the examiner should use it in an appropriate situation and conduct various studies to acquire high-quality images and to improve the understanding and proficiency of the equipment.

• Journal of the Korean Society of Radiology
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• v.84 no.5
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• pp.1009-1016
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• 2023

Radiofrequency ablation (RFA) is a minimally invasive treatment modality used as an alternative to surgery in patients with benign thyroid nodules and recurrent thyroid cancers. In Korea, RFA for thyroid nodules was first performed in 2002, and a large population study was published in 2008. The Task Force Committee of the Korean Society of Thyroid Radiology (KSThR) developed its first recommendations for RFA in 2009, which were revised in 2012 and 2018. The KSThR guideline was the first guideline for RFA of thyroid nodules worldwide and has become a guideline for physicians to perform thyroid RFA in Korea and other countries around the world. These guidelines have contributed significantly to the establishment and widespread use of RFA worldwide. In addition, since 2015, the KSThR has conducted intensive hands-on courses depending on the level of the participants. In this article, the authors introduce the history of eduction for RFA conducted by the KSThR and describe the learning curve of RFA and current training programs in Korea, along with future directions for training programs.

• The Journal of the Korea Contents Association
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• v.11 no.5
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• pp.242-251
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• 2011

A curriculum of study demands a change as period of time and society evolve. Therefore, at this point where changes are required, this study is to analyze and evaluate the curriculums which will enhance and improve current studies as a preceding stage. The research was based on the survey by groups of education experts and 19 universities with current curriculum of study in radiologic science, and their references. The study was focused on the scope of work by radiologic technologist, change of college systems, academic research about radiologic science, and the improvement and the future of radiologic science field in perspective to globalization and the digital era. In terms of work scope, angiography and interventional radiology at 6 to 8 schools, fluoroscopy at 4 schools, ultrasound and practices at 6 schools, magnetic resonance image at 2 schools were found to be unestablished. The basic medical subjects, humuan physiology, human anatomy and practices, medical terminology courses were set up at most schools; however, pathology at 5 schools, image anatomy at 6 schools, clinical medicine at 11 schools were yet opened. Among the basic science and engineering subjects, general biology and its practices at 11 schools, general physics and its practices at 14 schools, and general chemistry and its practices at 8 schools were established which is about a half from a total number of schools. Only 4-5 schools established digital subjects such as, health computer, computer programming, PACS which are the basic major subjects. In order to provide academic improvement in radiologic science, digitalized education and globalization, and basis for future-oriented education for the field of radiologic science, including expanded scope of work, it is acknowledged that curriculums that are opened and run at each school need to be standardized. Therefore, the need for introduction of certificate for the radiologic science education courses are suggested.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.2
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• pp.179-185
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• 2004

Purpose: Perinatal mortality rates have been used as a summary statistic for evaluating child health and medical status. Neonatal mortality rates have decreased over the past 30 years in Korea. To understand the current status of neonatal surgical gastrointestinal diseases in Daegu Busan area, we have studied about neonatal gastrointestinal diseases with their clinical features, postoperative outcome, and mortality rates. Methods: A clinical analysis on 202 neonates who underwent neonatal surgery from January 1996 to July 2003 at Pusan National University, Kyungpook National University, Youngnam University, and Daegu Catholic University was carried out. Results: The main diseases of surgical conditions were anorectal malformation (23.8%), atresia/stenosis of midgut (13.4%) and pyloric stenosis (13.4%). The male to female ratio was 2.8 : 1. Thirty-five cases (17.0%) had one or more associated anomalies including congenital heart disease, cryptoorchidism, hydronephrosis, and chromosomal anomaly. Twenty cases (10.0%) were diagnosed by antenatal ultrasound. Patients with esophageal atresia had the longest hospitalization for 54.6 days. Postoperative complications occurred in 18 cases (8.9%). The main postoperative complications were wound infection (3.5%) and anastomotic leakage (2.5%). Overall mortality was 5.9%. Diaphragmatic hernia showed the highest mortality rate (37.5%), and esophageal atresia (28.6%) and omphalocele (20.0%) were followed. Conclusion: The current status of neonatal surgical gastrointestinal diseases in Daegu Busan area has improved because the disease categories are various, postoperative complications and mortality rates are decreased.

• The Journal of Korean society of community based occupational therapy
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• v.10 no.1
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• pp.31-38
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• 2020

Objective : The purpose of this study is to investigate the effects of bilateral chewing exercise applied for 6 weeks on occlusion force and masseter muscle thickness in the elderly living in the community. Methods : This study recruited 25 community residents. All participants performed bilateral chewing exercise using equipment developed for the purpose of oral chewing exercise. The chewing exercise was divided into isometric and isotonic type and applied for about 20 minutes a day, five times a week for six weeks. For the evaluation, the masseter muscle thickness and the maximum occlusion force were measured three times at three week intervals using a portable ultrasound instrument and an occlusion force gauge. Results : As a result of the change in masseter muscle thickness, baseline, 3 weeks later, and 6 weeks later referred to 7.51±0.43, 7.63±0.44, and 7.83±0.46, respectively (F=3.819, p<.05). The post hoc test resulted in a significance between baseline and 6 weeks later (p=0.023). Similarly, as a result of the change in occlusion force, baseline, 3 weeks later, and 6 weeks later referred to 265±9.22, 268±9.57, and 271.59±10.16, respectively (F=3.031, p<.05). The post hoc test resulted in a significance between baseline and 6 weeks later (p=0.048). Conclusion : This study confirmed that bilateral chewing exercise was effective for increasing masseter muscle thickness and occlusion force in the elderly. Therefore, bilateral chewing exercise can be applied as a therapeutic exercise method for improving oral function.

• Clinical and Experimental Pediatrics
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• v.52 no.6
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• pp.655-660
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• 2009

Purpose : To compare birth weight between infants with a single umbilical artery (SUA) and normal infants, investigate the associated anomalies of infants with SUA and isolated SUA (no abnormality of external appearance on birth, except SUA), and determine the prognosis of infants with isolated SUA. Methods : Live-born infants with SUA (n=59) detected by physical examination from among 15,193 live births in seven university hospitals in Korea between January 1, 2004, to August 1, 2007, were reviewed retrospectively, with 236 normal infants serving as the control group. Results : A statistical difference was observed between the groups in birth weight and in vitro fertilization. The incidence of infants with SUA was 0.37%. Congenital malformations were observed in 21 infants with cardiovascular (n=15, 25.4%), gastrointestinal (n=2, 3.4%), genitourinary (n=9, 15.3%), neuromusculoskeletal (n=6, 10.2%), central nervous system (n=1, 1.7%), chromosomal (n=1, 1.7%), and other (n=3, 5.1%) abnormalities. There were 49 (83.1%) infants with isolated SUA in this study population; among them, the associated congenital malformations were cardiovascular (n=6, 12.2%) and genitourinary (n=6, 12.2%) abnormalities. Two infants with cyanotic heart disease were operated and four infants with acyanotic heart disease showed improvements without any treatment. Six infants with genitourinary abnormalities on renal ultrasound had mild hydronephrosis without further consequences. Conclusion : The incidence of structural abnormalities in the cardiovascular and genitourinary systems is high and the genitourinary anomalies associated with isolated SUA have relatively good prognosis.

• Journal of radiological science and technology
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• v.31 no.2
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• pp.161-169
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• 2008

Since measuring the size of kidney with sonography becomes an important index for diagnosis, treatment, and prognostic prediction in kidney disease, the accurate measurement and evaluation on this are clinically very important. Accordingly, the purpose of this study was to increase reproducibility and objectivity in measuring the size of kidney by enumerating factors that have an impact for measurement. It targeted 44 adults in Korea at the age of 21-27. It measured in order for both kidneys to be seen most largely while changing a subject-examiner's position in a state of fasting for 8 hours and a transducer's approaching direction. It compared a size of kidney by measuring, respectively, with the same method in 30 minutes and in 1 hour after drinking water in 700-1,000cc. In case of the lateral approach scan in decubitus position, the average length of the kidney both to the right and the left and the deviation of measurement to be the largest. In NPO(None Per Oral) state, the average length in the right kidney was 10.19cm, and the average length in the left kidney was 10.33cm. In 60 minutes after taking moisture, the average length in the right kidney was 10.94cm, and the average length in the left kidney was 11.13cm. In comparing the average length of the kidney in NPO state and its average length in 60 minutes after taking moisture, the size swelled by 7.3% for the length in the right kidney and by 7.7% in the left, thereby having been indicated to be statistically significant(P<0.003). The measurement in a size of kidney by using ultrasound may be measured differently depending on a patient's state of taking moisture and a transducer's approaching direction. It is thought that when the measurement in a size of kidney is especially important clinically, the intake and intake time in moisture need to be considered and that measuring with the posterior approach in prone position is a good method aiming to increase reproducibility in measuring length of the kidney.

• Radiation Oncology Journal
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• v.26 no.2
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• pp.96-103
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• 2008

Purpose: To conduct a nationwide academic hospital patterns of the practice status and principles of radiotherapy for prostate cancer. The survey will help develop the framework of a database of Korean in Patterns of Case Study. Materials and Methods: A questionnaire about radiation treatment status and principles was sent to radiation oncologists in charge of prostate cancer treatment at thirteen academic hospitals in Korea. The data was analyzed to find treatment principles among the radiation oncologists when treating prostate cancer. Results: The number of patients with prostate cancer and treated with radiation ranged from 60 to 150 per academic hospital in Seoul City and 10 to 15 outside of Seoul City in 2006. The primary diagnostic methods of prostate cancer included the ultrasound guided biopsy on 6 to 12 prostate sites(mean=9), followed by magnetic resonance imaging and a whole body bone scan. Internal and external immobilizations were used in 61.5% and 76.9%, respectively, with diverse radiation targets. Whole pelvis radiation therapy(dose ranging from 45.0 to 50.4 Gy) was performed in 76.9%, followed by the irradiation of seminal vesicles($54.0{\sim}73.8$ Gy) in 92.3%. The definitive radiotherapy doses were increased as a function of risk group, but the range of radiation doses was wide(60.0 to 78.5 Gy). Intensity modulated radiation therapy using doses greater than 70 Gy, were performed in 53.8% of academic hospitals. In addition, the simultaneous intra-factional boost(SIB) technique was used in three hospitals; however, the target volume and radiation dose were diverse. Radiation therapy to biochemical recurrence after a radical prostatectomy was performed in 84.6%; however, the radiation dose was variable and the radiation field ranged from whole pelvis to prostate bed. Conclusion: The results of this study suggest that a nationwide Korean Patterns of Care Study is necessary for the recommendation of radiation therapy guidelines of prostate cancer.

• Journal of Veterinary Clinics
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• v.29 no.2
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• pp.134-140
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• 2012

This retrospective study was performed to describe and evaluate ultrasonographic characteristics of splenic disorders and to pursue any relationship with cytologic or histopathologic diagnoses. Medical records were reviewed for patients that had undergone both abdominal ultrasonographic procedures and ultrasound-guided fine-needle aspiration (FNA) or surgical biopsy of splenic lesions or necropsy from January 2002 to July 2011 at Seoul National University Hospital for Animals. Total 124 dogs, 76 cases with FNA and 48 cases with biopsy, were available for this investigation. The age of dogs ranged from 2 to 17 years ($mean{\pm}SD$ = $9.54{\pm}3.34$ years), with the gender distribution of 61 females (26 spayed) and 63 males (40 neutered). In breed distribution, 114 were purebred dogs and 10 were mixed breed dogs. The dogs represented 26 breeds, with 113 dogs categorized into small-sized breeds. The ultrasonographic appearances of splenic disorders could be classified into 10 types including normal appearance, depending on the distribution and echogenicity of splenic lesions as well as the increase in spleen size and diffuse parenchymal changes. Among 124 cases, 44 (35.4%) had hypoechoic nodules/masses with the highest frequency, followed by 23 (18.5%) with multiple small hypoechoic nodules. Of 124 cases, 70 (56.5%) were benign and 54 (43.5%) were malignant lesions at cytologic or histopathologic results. Each ultrasonographic appearance had variable cytologic or histopathologic diagnoses. However, diffuse heterogenicity and diffuse hypoechogenicity were significantly associated with malignancy (p < 0.05), whereas hyperechoic nodules/masses were more often associated with benignity (p < 0.05). Based on our results, it may be considered that the ultrasonographic examination for spleen could be able to provide the least information necessary for benign and malignant lesions in prioritizing differential diagnoses.

• Korean Journal of Optics and Photonics
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• v.31 no.1
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• pp.1-6
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• 2020

The chest wall, an organ directly affected by environmental particles through respiration, consists of ribs, a pleural layer and intercostal muscles. To diagnose early and treat disease in this body part, it is important to visualize the details of the chest wall, but the structure of the pleural layer cannot be seen by chest computed tomography or ultrasound. On the other hand, optical coherence tomography (OCT), with a high spatial resolution, is suited to observe pleural-layer response to talc, one of the fine materials. However, intensity-based OCT is weak in providing information to distinguish the detailed structure of the chest wall, and cannot distinguish the reaction of the pleural layer from the change in the muscle by the talc. Polarization-sensitive OCT (PS-OCT) takes advantage of the fact that specific tissues like muscle, which have optical birefringence, change the backscattered light's polarization state. Moreover, the birefringence of muscle associated with the arrangement of myofilaments indicates the muscle's condition, by measuring retardation change. The PS-OCT image is interpreted from three major perspectives for talc-exposure chest-wall imaging: a thickened pleural layer, a separation between pleural layer and muscle, and a phase-retardation measurement around lesions. In this paper, a rabbit chest wall after talc pleurodesis is investigated by PS-OCT. The PS-OCT images visualize the pleural layer and muscle, respectively, and this system shows different birefringence of normal and damaged lesions. Also, an analyisis based on phase-retardation slope supports results from the PS-OCT image and histology.